Roads, bridges, pipelines, and other types of infrastructure in Alaska and elsewhere in the Arctic will deteriorate faster than expected due to a failure by planners to account for the structures’ impact on adjacent permafrost, researchers have found.
The findings were presented in a May 31 paper in The Cryosphere, a publication of the European Geosciences Union. In it, 13 experts in their fields, led by Thomas Schneider von Deimling of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Potsdam, Germany.
The research paper determined that planners must account for the sideward repercussions of their projects in addition to the usual projection of the direct top-down effects when working on infrastructure projects in permafrost.
The researchers focused on a portion of the Dalton Highway on Alaska’s North Slope about 10 miles south of the Prudhoe Bay oil fields. Sensors monitored the temperature at seven locations, three to the west of the highway and four on the east.
Once called the North Slope Road, the 800-mile Dalton Highway begins north of Fairbanks and ends at Deadhorse, an unincorporated community near the Arctic Ocean and the Prudhoe Bay Oil Fields.
The highway runs parallel to the Trans-Alaska Pipeline System, and with only three small towns along the highway, is also the most isolated road in the United States.
And it is interesting that the researchers found that top-down thawing isn’t confined to the area just beneath the road surface. Instead, the thawing spreads outward away from the road, itself.
This thawing destabilized the embankment and subgrade, resulting in the formation of taliks — areas of ground that have thawed and remain unfrozen year-round — under a roadway’s toe, the prepared zone at the base of the embankment and abutting the natural terrain.
Based on this finding, the researchers write that this will result “in an accelerating thaw rate and earlier than anticipated road failure,” adding a warning that other types of Arctic infrastructure such as pipelines, fuel storage tanks, and airports will fail sooner than projected.
The authors write that their findings show a shortcoming in other infrastructure risk assessment methods, which fail to adequately capture changes in permafrost and don’t analyze the interaction between the infrastructure and the adjacent ground.
The author’s conclude it is “crucial to consider climate change effects when planning and constructing infrastructure on permafrost as a transition from a stable to a highly unstable state can well occur within the infrastructure’s service lifetime (about 30 years).”
